B Can an Object with N Dimensions Exist in N-1 Dimensions?

  • Thread starter Thread starter duyix
  • Start date Start date
  • Tags Tags
    2d 3d Space
Click For Summary
An object with N dimensions cannot exist entirely in N-1 dimensions, as the fundamental properties of dimensions dictate that each dimension requires a corresponding degree of freedom. An infinitely flat object, such as a plane, is inherently two-dimensional and can be described by two non-parallel direction vectors, indicating it has only two degrees of freedom. Various mathematical results, including those related to embedding spaces, support the conclusion that higher-dimensional objects cannot be fully represented in lower-dimensional spaces. The discussion highlights the importance of understanding the definitions of dimensions and the implications of embedding in mathematical contexts. Overall, the consensus is that dimensionality is a strict constraint that cannot be bypassed.
duyix
Messages
1
Reaction score
1
I am concerned that this question may instead be a philosophical one although if it it mathematical, any insights would be very appreciated. The question is this; could an object of N dimensions exist entirely in N-1 dimensions? In other words, could an infinitely flat object have 3 degrees of freedom and also be able to fit entirely in 2D space? Thank you and please excuse any naivety
 
Mathematics news on Phys.org
duyix said:
The question is this; could an object of N dimensions exist entirely in N-1 dimensions?
No, it's not possible.

duyix said:
In other words, could an infinitely flat object have 3 degrees of freedom and also be able to fit entirely in 2D space? [\quote]
If by "infinitely flat object" you mean "a plane" it's already a two-dimensional object that can be determined by two nonparallel direction vectors. I.e., two degrees of freedom.
 
Last edited:
There are different definitions of the term Dimension. One of them is that of number of data points needed to fully describe every point in the n-th dimensional object. And that number is precisely n.
There are results to the effect that ##\mathbb R^{n+k} ; k >0 ##; k a positive Integer, cannot be embedded in ##\mathbb R^n ##. There are similar results for n-spheres ## S^n ##. that cannot be embedded in ## \mathbb R^n ## or lower IIRC, the main result is that of Borsuk -Ulam.

Edit: A 1-dimensional object embedded in n-space is describable as ##(f_1(x), f_2(x),...,f_n(x))##.
An m-dimensional object in k-space is describable as ## (f_1(x_1,..., x_m), f_2(x_1,x_2,..,x_m),,..,f_k(x_1,x_2,..,x_m) )##
 
Last edited:
Thread 'Erroneously  finding discrepancy in transpose rule'
Obviously, there is something elementary I am missing here. To form the transpose of a matrix, one exchanges rows and columns, so the transpose of a scalar, considered as (or isomorphic to) a one-entry matrix, should stay the same, including if the scalar is a complex number. On the other hand, in the isomorphism between the complex plane and the real plane, a complex number a+bi corresponds to a matrix in the real plane; taking the transpose we get which then corresponds to a-bi...

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
29
Views
3K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K